The present invention relates to a spray shield for dental handpieces that can be used to minimize the amount of material that escapes into the air when using a dental handpiece, and to direct the spray of the material on a working surface and can be used, for example, with a handpiece which is used to abrasively clean teeth.
Stains on teeth may originate from various sources or causes including smoking, tabacco chewing, excessive drinking of tea or from vegetable origin. Calculus is of several different types, especially serumal and salivary, and calculus deposits ordinarily form in pockets between the teeth and the surrounding soft tissues, the serumal calculus originating from the saliva. These constituents precipitate and bond themselves to the exposed tooth surfaces.
It is known in the art to clean teeth using air-abrasive equipment which is particularly useful for removing stains from crevices in the teeth.
By air-abrasive equipment, it is meant that an apparatus, particularly a dental handpiece, is provided in which a gas propels a mildly abrasive powder and preferably a liquid against a tooth surface, for example, to clean teeth using a mildly abrasive mixture of said powder and liquid. The equipment is called air-abrasive since the gas used for propelling the powder will preferably be air.
In the use of air-abrasive equipment for dental purposes, the delivery and dispersal of abrasive particles in air suspension in the mouth is objectionable and in some prior equipment employed for tooth cutting, vacuum means has been employed to capture the abrasive particles. This, however, is bulky and cumbersome. In some prior systems it has also been contemplated to wash the teeth with water following the abrasive treatment, but such subsequent washing does not overcome the objectionable initial distribution of the abrasive particles on the soft tissues and other parts of the mouth. To alleviate these difficulties and to provide air-abrasive prophylaxis equipment adapted to the convenient and effective removal of stain and or calculus in a manner which is simple and which produces minimum discomfort to the patient, a handpiece was provided having a nozzle with an air-abrasive discharge passage, and a water discharge passage surrounding the air-abrasive passage, together with control means by which warmed water was delivered for discharge through the water passage, and the air-abrasive and water streams were coordinated to capture the abrasive particles after they were dispensed.
In the handpiece provided in the prior art, the water discharge passage is directed to impinge upon the surface of the tooth being cleaned in an area immediately adjacent to or overlapping the area of impingement of the air-abrasive stream. Preferably a water stream is provided to form a curtain surrounding the air-abrasive stream. In its most effective embodiment, the motion of the powder and liquid as it is being dispensed from the handpiece causes a mixing of the powder and water to form a slurry. It is an air propelled slurry of abrasive powder and water which provides the most effective cleaning of teeth.
Although forming a slurry greatly minimizes the amount of material that escapes into the atmosphere, under the pressure used in the handpiece, it is inevitable that at least some of the fine spray or mist of material will escape into the atmosphere.
Also, as now presently used, the above described handpieces are held in the hand a recommended distance from the working area which is estimated by the practitioner. If the handpiece is held too far from the working area, it is difficult for the practitioner to avoid hitting restorative areas or sensitive gingival tissue in the mouth which can be damaged.
Also, it is sometimes difficult for the practitioner to see where he is cleaning in the posterior areas of the mouth, and there is a need in the art for a device by which the practitioner can maintain a desirable working distance by other means when using a tool for air-abrasive cleaning of teeth.
It is the object of the present invention to overcome the above described problems in the prior art.